1. Field of the Invention
The present invention relates to a liquid composition, a set of a liquid composition and an ink, and an image recording method. In particular, the present invention relates to a liquid composition, a set of the liquid composition and an ink, an ink jet recording apparatus, and an image forming method in the case where the liquid composition and the ink are used in combination to conduct printing on a recording medium.
2. Related Background Art
Proposed as an ink jet recording method is a method including preparing a liquid for forming a good image separately of typical ink jet inks; and applying the liquid to a recording medium prior to ejection of a recording ink, to thereby form an image. For example, a method is disclosed, which involves applying a liquid having a basic polymer; and conducting recording with an ink containing an anionic dye (see, for example, Japanese Patent Application Laid-open No. S63-60783).
In the above method, the dye itself is precipitated on a recording medium in order to suppress bleeding of an image or to improve water resistance of the image. However, the method provides an insufficient suppressing effect on bleeding between color inks having different hues. In addition, the precipitated dye is apt to be unevenly distributed on recording paper, so uniformity of image quality may reduce. In particular, when plain paper is used as a recording medium, coating property with respect to pulp fibers is poor, so the tendency of a reduction in uniformity of image quality is remarkably observed.
On the other hand, an ink set is proposed as a system using a pigment as a colorant of ink, which is used by combining an ink containing a pigment dispersion and an ink containing a polyvalent metal for the purpose of alleviating bleeding in a multi-color printed product (see, for example, Japanese Patent Application Laid-open No. H09-118850). In this case, there is, for example, a constraint that a polyvalent metal whose compatibility with a colorant, that is, stability in ink is taken into consideration must be used for the ink containing a polyvalent metal. Accordingly, there arises a problem in that a sufficient image density is hardly obtained.
Proposed as a method of solving the above problem is a recording method (hereinafter, referred to as a two-liquid system) including applying a liquid composition containing a polyvalent metal to a recording medium; and conducting printing with an ink capable of reacting with the liquid composition to improve uniformity of an image and an image density. For example, an ink jet recording method is disclosed, which involves conducting printing with an ink jet recording liquid of an ink having a specific acid value, containing a water-soluble resin and a pigment dissolved into an aqueous medium in the presence of a basic compound, and having a specific surface tension on a recording paper obtained by applying a predetermined amount of a solution containing a dissociative polyvalent metal salt to plain paper (see, for example, Japanese Patent Application Laid-open No. 2000-94825).
Meanwhile, warping or curling of a recording medium, so-called curling phenomenon may occur when moisture is applied to the recording medium. Several methods have been conventionally proposed to alleviate and suppress the curling phenomenon. For example, an ink jet ink having 4 or more hydroxyl groups in its molecular structure and containing a solid substance that can be dissolved into water or an aqueous organic solvent is proposed (see, for example, Japanese Patent Application Laid-open No. H04-332775). In addition, an ink containing a saccharide, a sugar alcohol, or a specific amide compound is proposed as an anti-curling agent (see,for example, Japanese Patent Application Laid-open No. H06-157955, Japanese Patent Application Laid-open No. H06-240189, Japanese Patent Application Laid-open No. H09-165539, and Japanese Patent Application Laid-open No. H09-176538). In addition, an ink containing a combination of a specific polyhydric alcohol and glycerin is proposed (see, for example, Japanese Patent Application Laid-open No. H10-130550). In addition, an ink containing a solvent, a polymer binder, a dye mordant, a water-soluble anti-curling agent, a water-soluble desizing compound, a light-proof compound, an antifoaming agent, or the like is proposed (see, for example, Japanese Patent Application Laid-open No. 2000-198267).